---
title: Denier
description: Adapter that always returns a precondition denial.
location: https://istio.io/docs/reference/config/policy-and-telemetry/adapters/denier.html
layout: protoc-gen-docs
generator: protoc-gen-docs
supported_templates: listentry,quota,checknothing
aliases:
  - /docs/reference/config/adapters/denier.html
number_of_entries: 2
---
<p>The <code>denier</code> adapter is designed to always return a denial to precondition
checks. You can specify the exact error to return for these denials.</p>

<p>This adapter supports the <a href="https://istio.io/docs/reference/config/policy-and-telemetry/templates/checknothing/">checknothing template</a>,
the <a href="https://istio.io/docs/reference/config/policy-and-telemetry/templates/listentry/">listentry template</a>,
and the <a href="https://istio.io/docs/reference/config/policy-and-telemetry/templates/quota/">quota template</a>.</p>

<h2 id="Params">Params</h2>
<section>
<p>Configuration format for the Denier adapter.</p>

<table class="message-fields">
<thead>
<tr>
<th>Field</th>
<th>Type</th>
<th>Description</th>
<th>Required</th>
</tr>
</thead>
<tbody>
<tr id="Params-status">
<td><code>status</code></td>
<td><code><a href="#google-rpc-Status">Status</a></code></td>
<td>
<p>The error to return when denying a request.</p>

</td>
<td>
No
</td>
</tr>
<tr id="Params-valid_duration">
<td><code>validDuration</code></td>
<td><code><a href="https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#duration">Duration</a></code></td>
<td>
<p>The duration for which the denial is valid.</p>

</td>
<td>
No
</td>
</tr>
<tr id="Params-valid_use_count">
<td><code>validUseCount</code></td>
<td><code>int32</code></td>
<td>
<p>The number of times the denial may be used.</p>

</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</section>
<h2 id="google-rpc-Status">google.rpc.Status</h2>
<section>
<p>The <code>Status</code> type defines a logical error model that is suitable for
different programming environments, including REST APIs and RPC APIs. It is
used by <a href="https://github.com/grpc">gRPC</a>. The error model is designed to be:</p>

<ul>
<li>Simple to use and understand for most users</li>
<li>Flexible enough to meet unexpected needs</li>
</ul>

<h3 id="overview">Overview</h3>

<p>The <code>Status</code> message contains three pieces of data: error code, error
message, and error details. The error code should be an enum value of
<em>google.rpc.Code</em>, but it may accept additional error codes
if needed.  The error message should be a developer-facing English message
that helps developers <em>understand</em> and <em>resolve</em> the error. If a localized
user-facing error message is needed, put the localized message in the error
details or localize it in the client. The optional error details may contain
arbitrary information about the error. There is a predefined set of error
detail types in the package <code>google.rpc</code> that can be used for common error
conditions.</p>

<h3 id="language-mapping">Language mapping</h3>

<p>The <code>Status</code> message is the logical representation of the error model, but it
is not necessarily the actual wire format. When the <code>Status</code> message is
exposed in different client libraries and different wire protocols, it can be
mapped differently. For example, it will likely be mapped to some exceptions
in Java, but more likely mapped to some error codes in C.</p>

<h3 id="other-uses">Other uses</h3>

<p>The error model and the <code>Status</code> message can be used in a variety of
environments, either with or without APIs, to provide a
consistent developer experience across different environments.</p>

<p>Example uses of this error model include:</p>

<ul>
<li><p>Partial errors. If a service needs to return partial errors to the client,
it may embed the <code>Status</code> in the normal response to indicate the partial
errors.</p></li>

<li><p>Workflow errors. A typical workflow has multiple steps. Each step may
have a <code>Status</code> message for error reporting.</p></li>

<li><p>Batch operations. If a client uses batch request and batch response, the
<code>Status</code> message should be used directly inside batch response, one for
each error sub-response.</p></li>

<li><p>Asynchronous operations. If an API call embeds asynchronous operation
results in its response, the status of those operations should be
represented directly using the <code>Status</code> message.</p></li>

<li><p>Logging. If some API errors are stored in logs, the message <code>Status</code> could
be used directly after any stripping needed for security/privacy reasons.</p></li>
</ul>

<table class="message-fields">
<thead>
<tr>
<th>Field</th>
<th>Type</th>
<th>Description</th>
<th>Required</th>
</tr>
</thead>
<tbody>
<tr id="google-rpc-Status-code">
<td><code>code</code></td>
<td><code>int32</code></td>
<td>
<p>The status code, which should be an enum value of
<em>google.rpc.Code</em>.</p>

</td>
<td>
No
</td>
</tr>
<tr id="google-rpc-Status-message">
<td><code>message</code></td>
<td><code>string</code></td>
<td>
<p>A developer-facing error message, which should be in English. Any
user-facing error message should be localized and sent in the
<a href="#google-rpc-Status-details">google.rpc.Status.details</a> field, or localized
by the client.</p>

</td>
<td>
No
</td>
</tr>
<tr id="google-rpc-Status-details">
<td><code>details</code></td>
<td><code><a href="https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#any">Any[]</a></code></td>
<td>
<p>A list of messages that carry the error details.  There is a common set of
message types for APIs to use.</p>

</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</section>
